RNAi-mediated human Nestin silence inhibits proliferation and migration of malignant melanoma cells by G1/S arrest via Akt-GSK3β-Rb pathway.

Human Nestin (hNestin) has been found to express in melanoma, and its expression is positively correlated with the advanced stage of melanoma. However, the precise role of hNestin in the development of melanoma has not been fully understood. The present study aimed to explore the role of hNestin in the proliferation and invasion of melanoma cells. The lentivirus vector carrying a short hairpin RNAs (shRNAs) targeting hNestin (hNestin-shRNA-LV) was stably infected into human melanoma cells UACC903, which expressed high levels of hNestin. The effects of hNestin knockdown on the proliferation, apoptosis, migration of melanoma cells and the related signaling pathways were investigated by immunofluorence, Western blotting and reverse transcription polymerase chain reaction (RT-PCR), respectively. The results showed that hNestin was expressed in most melanoma specimens and the melanoma cells studied. Knockdown of hNestin expression significantly inhibited the proliferation of melanoma cells, blocked the formation of cell colony, arrested cell cycle at G₁/S stage and suppressed the activation of Akt and GSK3β. hNestin-silent cells also showed a sheet-like appearance with tight cell-cell adhesion, decreased membrane expression of N-cadherin and β-catenin, and attenuated migration. Furthermore, hNestin silence resulted in the inhibition of tumor growth in vivo. Our study indicates that hNestin knockdown suppresses the proliferation of melanoma cells, which might be through affecting Akt-GSK3β-Rb pathway-mediated G₁/S arrest, and hNestin silence inhibits the migration by selectively modulating the expression of cell adhesion molecules in the process of epithelial-mesenchymal transition.